Date Functions in SQL Server and MySQL

SQL Server and MySQL are the #1 choice for people working with massive databases. Among numerous reasons, built-in functions in SQL Server and MySQL are the primary reasons for everyone’s preference. Talking of the built-in functions, we cannot overlook the easy-to-use date functions that SQL Server and MySQL offer their users.

Date functions are one of the essential features in these databases, and you might use them frequently when working on real-life projects. So, if you are learning MySQL and SQL Server, it’s best to know the date functions before anything. These functions are easy to understand, and anyone can use them with proper practice.

Do you want to master the date functions in SQL Server and MySQL? This article is an excellent start. We will help you dive deep into each date function, separately for MySQL and SQL Server, with a detailed explanation and appropriate syntax. It’s not over yet! This post will help you go ahead and understand how these databases store dates by discussing the SQL date time format. Stay tuned!

Looking at the Data Types for Dates

Before understanding the date functions, we must go through the data types used in SQL Server and MySQL to store date values in the database. So, here are the data types leveraged to store date functions. Have a look! 

To accommodate a date or date/time value in a database, MySQL offers the following data types:

1. DATE() format: YYYY-MM-DD
2. DATETIME() format: YYYY-MM-DD HH:MI:SS
3. TIMESTAMP() format: YYYY-MM-DD HH:MI:SS
4. YEAR() format: YYYY or YY

The following data types are available in SQL Server to store a date or date/time value in the database:

1. DATE() format YYYY-MM-DD
2. DATETIME() format: YYYY-MM-DD HH:MI:SS
3. SMALLDATETIME() format: YYYY-MM-DD HH:MI:SS
4. TIMESTAMP() format: a unique number

MySQL Date Functions

Numerous built-in functions in MySQL let you work with data. Date functions, time functions, mathematical functions, string functions, and other categories are used to group these functions.

Let’s focus on MySQL date functions in this section. In MySQL, date functions provide you with a wide range of choices for modifying, fetching, converting, and computing date, time, and DateTime expressions. 

The following are some essential date methods for MySQL:

• DATE() 

MySQL includes the DATE() function by default. The date portion of a DateTime expression is extracted using this function. The date is returned by the DATE() method after accepting a date value as an input. You can use the DATE() function in MySQL to determine the date for a given date or a DateTime. The date parameter represents the valid date or DateTime.

Syntax: DATE (‘Expression’);

• NOW()

Whether the NOW() function is used in a string or a numeric environment, the return type is either ‘YYYY-MM-DD HH:MM:SS’ or ‘YYYYMMDDHHMMSS.uuuuuu.’ You can use MySQL’s NOW() method to check the current date and time value.

Syntax: NOW()

• CURDATE()

CURDATE() returns the current date in the MySQL method. The CURRENT DATE() function is equivalent to this function. The date is returned in either the string format “YYYY-MM-DD” or as YYYYMMDD (numeric). 

Syntax: CURDATE()

• CURTIME()

The MySQL CURTIME() method is used to determine the current time. Whether the function is used in a string or a numeric environment, it returns the present time in the ‘hh:mm:ss’ or ‘hhmmss’ format.

Syntax: CURTIME(fsp)

• EXTRACT()

A portion of the DATE and DATETIME data are extracted using the EXTRACT() function. The DATE and DATETIME functions are connected to it. For instance, we can take the DATE and DATETIME values supplied in the function argument and extract the month component, year section, day, minutes, seconds, microseconds, etc.

Syntax: EXTRACT(unit_value FROM date_value);  

• DATE_ADD()

The Date function in MySQL has several sub-functions, one of which, DATE ADD(), is used to change the date. We may change the date using the DATE_ADD method by adding days, years, or months.

Syntax: DATE_ADD(date,INTERVAL expr type)

• DATE_SUB()

The MySQL database server includes a built-in function called date sub() that subtracts a time or date value from a date or DateTime value and returns the result as a date or DateTime.

Syntax: DATE_SUB (start_date,time expression unit)

• DATEDIFF()

The DATEDIFF function in MySQL determines how many days there are between two DATE, DATETIME, or TIMESTAMP values. 

Syntax: DATEDIFF(date_expression_1,date_expression_2);

• DATE_FORMAT()

The DATE FORMAT() function in MySQL is used to format a specified date according to the format value provided. For example, a date is given, and this function formats the date according to the format parameters provided.

Syntax: DATE_FORMAT(date, format)

A Glimpse of the SQL Server Date Functions

Like MySQL, SQL Server gives you many date functions. Here are some of the main methods mentioned below:

• GETDATE()

The GETDATE() function returns the time and date of the current database system in the format “YYYY-MM-DD hh:mm:ss.mmm.”

Syntax: SELECT GETDATE(); 

• DATEPART()

In SQL Server, the DATEPART() function returns a particular portion of a date. The output of this function is an integer value.

Syntax: DATEPART(interval, date)

• DATEADD()

A time/date interval is added to the date via the DATEADD() function, which returns the original date.

Syntax: DATEADD(interval, number, date)

• DATEDIFF()

Another date function is the DATEDIFF() function in SQL Server, which returns the difference between two dates.

Syntax: DATEDIFF(interval, date1, date2)

• CONVERT()

A general function called CONVERT() transforms an expression from one data type to another. You can show the date and time data in various formats using the CONVERT() function.

Syntax: CONVERT(data_type(length),expression,style)

Wrapping Up! 

These were all data functions you can use when working with MySQL and SQL Server databases. It might take some to understand these functions and learn their syntax. However, you can master them with practice and use the methods like a database pro.

You will learn all you need to know about SQL databases and how to use them in your applications by taking this SQL certification course. This course covers the correct structure of a database, the creation of efficient SQL clauses and statements, and the management of a scalable SQL database.   

Similarly, MySQL and SQL Server have other built-in functions that come in handy when you handle various databases. If you want to grasp more about these functions, follow Simplilearn online learning for more information.